package com.cd.university.config.security.validate.image;

import com.cd.university.config.security.properties.SecurityProperties;
import com.cd.university.config.security.validate.ValidateCode;
import com.cd.university.config.security.validate.ValidateCodeGenerator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.context.request.ServletWebRequest;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 图形验证码的生成
 * @author 陈栋
 * @create 2021/9/4 11:01
 */
public class ImageCodeGenerator implements ValidateCodeGenerator {

    /**
     * 使用默认的配置类，下面的程序做了扩展可以使用前端传过来的配置
     */
    @Autowired
    private SecurityProperties securityProperties;

    /**
     * 生成图形中的验证码，并且把验证码封装到一个ImageCode(ValidateCode子类)实例中返回
     * @param request 请求和响应
     * @return ImageCode实例
     */
    @Override
    public ValidateCode generate(ServletWebRequest request) {
        // 这样配置可以使前端传递过来的参数先被应用
        // 第一参数为request第二个参数为request里面parameter的name
        // 第三个参数为默认值，如果前面通过name没有拿到的话就会使用第三个参数
        int width = ServletRequestUtils.getIntParameter(request.getRequest(),
                "width",
                securityProperties.getCode().getImageCode().getWidth());
//        int width = securityProperties.getCode().getImage().getWidth();
        int height = ServletRequestUtils.getIntParameter(request.getRequest(),
                "height",
                securityProperties.getCode().getImageCode().getHeight());
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

        Random random = new Random();

        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }

        String sRand = "";
        // 生成一个指定位数的验证码
        for (int i = 0; i < ServletRequestUtils.getIntParameter(request.getRequest(),"length",securityProperties.getCode().getImageCode().getLength()); i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(rand, 13 * i + 6, 16);
        }

        g.dispose();
        // 图片的Buff流，图片生成的code码，默认过期时间60秒
        return new ImageCode(image, sRand, securityProperties.getCode().getImageCode().getExpireIn());
    }

    /**
     * 生成随机背景条纹
     *
     * @param fc
     * @param bc
     * @return
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
}
